The amount you make depends on your specialty. For those who work for petroleum companies or metallic mineral fields, you may find that your salary depends on the market. If the price of gold goes up, there are plenty of jobs and money for geologists. When oil dries up, employment options look bleak and people get laid off. According to Geology.com, geologists with 0-2 years of experience make an average salary of a little over $80k. Experienced petroleum geologists can make around $215k.
You will not make that kind of money if you work for the government. Those with a bachelor's degree can earn $25k, those with a master's may earn $30k, and those with a Ph.D. can earn $45k. If you work for a company, expect to make $30k with a bachelor’s degree, $35k with a master’s degree, and $40k with a doctorate degree.
Some geologists become self-employed and work as consultants for companies. The upside is all the extra time you’ll have on your hands, during which you can try to determine what caused the Cryogenian ice age, but the downside is that it is up to you to drum up business. However, your rock collection magically turns into a tax write-off.